Tunable nanolayered coatings for effective treatment of implant-related bacterial infection in bone


Jouha Min


Jouha Min, Richard D. Braatz, Myron Spector, Paula T. Hammond

Author Affiliation: 

Department of Chemical Engineering, Massachusetts Institute of Technology David H. Koch Institute for Integrative Cancer Research


In developing new generations of coatings for medical devices and tissue engineering scaffolds, there is a need for thin coatings that provide controlled release of multiple therapeutics. For orthopedic applications, a promising strategy to accelerate implant-tissue integration and improve surgical outcomes is to deliver an antibiotic and a growth factor for healing bone defects while preventing infection at the implant site. To this end, a series of self-assembled, polymer- based conformal coatings, built by using a water-based layer-by-layer (LbL) assembly technique—a method involving the alternate adsorption of oppositely charged polymers—was generated as biomimetic implant surface coatings that are conformal and only microns in thickness. These LbL coatings consist of two parts: a base osteoinductive component containing bone morphogenetic protein-2 (rhBMP-2) beneath an antibacterial component containing gentamicin (GS). For the fabrication of compartmentalized composite films with controlled and staged release profiles, we presented a new strategy—implementation of laponite clay barriers— that allows for a physical separation of multiple components by controlling interlayer diffusion and thus enabling separation of the components between different therapeutic containing multilayers. To our knowledge, this is the first study demonstrating that multi-drug LbL coatings can be tuned for specific orthopedic applications involving infection treatment and bone regeneration. The general demonstration of controlled multicomponent release from a thin film coating platform is a significant advance for a variety of surface delivery applications.